001package org.cpsolver.instructor.criteria; 002 003import java.util.Collection; 004import java.util.HashSet; 005import java.util.Set; 006 007import org.cpsolver.ifs.assignment.Assignment; 008import org.cpsolver.ifs.model.Constraint; 009import org.cpsolver.ifs.util.DataProperties; 010import org.cpsolver.instructor.constraints.SameInstructorConstraint; 011import org.cpsolver.instructor.model.TeachingAssignment; 012import org.cpsolver.instructor.model.TeachingRequest; 013 014/** 015 * Same Instructor. This criterion counts how well are the soft Same Instructor Constraints (see {@link SameInstructorConstraint}) met. 016 * 017 * @version IFS 1.3 (Instructor Sectioning)<br> 018 * Copyright (C) 2016 Tomáš Müller<br> 019 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 020 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 021 * <br> 022 * This library is free software; you can redistribute it and/or modify 023 * it under the terms of the GNU Lesser General Public License as 024 * published by the Free Software Foundation; either version 3 of the 025 * License, or (at your option) any later version. <br> 026 * <br> 027 * This library is distributed in the hope that it will be useful, but 028 * WITHOUT ANY WARRANTY; without even the implied warranty of 029 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 030 * Lesser General Public License for more details. <br> 031 * <br> 032 * You should have received a copy of the GNU Lesser General Public 033 * License along with this library; if not see 034 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 035 */ 036public class SameInstructor extends InstructorSchedulingCriterion { 037 038 public SameInstructor() { 039 setValueUpdateType(ValueUpdateType.NoUpdate); 040 } 041 042 @Override 043 public double getWeightDefault(DataProperties config) { 044 return 10.0; 045 } 046 047 @Override 048 public double getValue(Assignment<TeachingRequest.Variable, TeachingAssignment> assignment, TeachingAssignment value, Set<TeachingAssignment> conflicts) { 049 double ret = 0.0; 050 for (Constraint<TeachingRequest.Variable, TeachingAssignment> c : value.variable().constraints()) 051 if (c instanceof SameInstructorConstraint) 052 ret += ((SameInstructorConstraint)c).getCurrentPreference(assignment, value); 053 return ret; 054 } 055 056 @Override 057 public double getValue(Assignment<TeachingRequest.Variable, TeachingAssignment> assignment, Collection<TeachingRequest.Variable> variables) { 058 double ret = 0; 059 Set<Constraint<TeachingRequest.Variable, TeachingAssignment>> constraints = new HashSet<Constraint<TeachingRequest.Variable, TeachingAssignment>>(); 060 for (TeachingRequest.Variable req: variables) { 061 for (Constraint<TeachingRequest.Variable, TeachingAssignment> c : req.constraints()) { 062 if (c instanceof SameInstructorConstraint && constraints.add(c)) 063 ret += ((SameInstructorConstraint)c).getContext(assignment).getPreference(); 064 } 065 } 066 return ret; 067 } 068 069 @Override 070 protected double[] computeBounds(Assignment<TeachingRequest.Variable, TeachingAssignment> assignment) { 071 double[] bounds = new double[] { 0.0, 0.0 }; 072 for (Constraint<TeachingRequest.Variable, TeachingAssignment> c: getModel().constraints()) { 073 if (c instanceof SameInstructorConstraint && !c.isHard()) 074 bounds[1] += Math.abs(((SameInstructorConstraint)c).getPreference()) * (1 + (c.variables().size() * (c.variables().size() - 1)) / 2); 075 } 076 return bounds; 077 } 078 079 @Override 080 public double[] getBounds(Assignment<TeachingRequest.Variable, TeachingAssignment> assignment, Collection<TeachingRequest.Variable> variables) { 081 double[] bounds = new double[] { 0.0, 0.0 }; 082 Set<Constraint<TeachingRequest.Variable, TeachingAssignment>> constraints = new HashSet<Constraint<TeachingRequest.Variable, TeachingAssignment>>(); 083 for (TeachingRequest.Variable req: variables) { 084 for (Constraint<TeachingRequest.Variable, TeachingAssignment> c : req.constraints()) { 085 if (c instanceof SameInstructorConstraint && !c.isHard() && constraints.add(c)) 086 bounds[1] += Math.abs(((SameInstructorConstraint)c).getPreference()) * ((c.variables().size() * (c.variables().size() - 1)) / 2); 087 } 088 } 089 return bounds; 090 } 091 092 @Override 093 public String getAbbreviation() { 094 return "SameInstructor"; 095 } 096}